diff --git a/include/bx/fpumath.h b/include/bx/fpumath.h
index d2e58e3..468480d 100644
--- a/include/bx/fpumath.h
+++ b/include/bx/fpumath.h
@@ -8,6 +8,7 @@
 #ifndef BX_FPU_MATH_H_HEADER_GUARD
 #define BX_FPU_MATH_H_HEADER_GUARD
 
+#include "bx.h"
 #include <math.h>
 #include <string.h>